It's possible that you can. Your ability to breastfeed after a breast reduction depends on how the surgery was performed and how many milk ducts and nerves remain intact. Your breasts will most likely make milk when baby arrives — but how much of that milk will have a clear route to baby's mouth is hard to predict.
Prepare for breastfeeding as any other mom-to-be should: read, watch videos, and talk to other moms. Learn as much as you can about how to help baby latch and nurse in the first days of life, so that he can stimulate your milk production and effectively remove the milk that does have a way out.
When baby arrives, give breastfeeding a shot. You may find that you can exclusively breastfeed after all. Or, you might be able to partially breastfeed baby. (Some breast milk is always better than none.) Have your doctor keep a close eye on baby's weight gain and dirty diaper output in the first few days of life. If he isn't getting enough to eat at the breast, you will need to supplement his diet with formula.